Patents by Inventor Takashi Oshima

Takashi Oshima has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20150249459
    Abstract: To compensate for non-linearity of an AD conversion unit and non-linearity of a DA conversion unit in an electronic system including the DA conversion unit and the AD conversion unit, an electronic system includes an A/D conversion unit, a D/A conversion unit, an AD conversion compensation unit, a DA conversion compensation unit, and a calibration unit. During a calibration operation period, the calibration unit sets an operating characteristic of the AD conversion compensation unit and an operating characteristic of the DA conversion compensation unit. The operating characteristic of the AD conversion compensation unit set during the calibration operation period compensates for non-linearity of AD conversion of the A/D conversion unit. The operating characteristic of the DA conversion compensation unit set during the calibration operation period compensates for non-linearity of DA conversion of the D/A conversion unit.
    Type: Application
    Filed: May 13, 2015
    Publication date: September 3, 2015
    Inventors: Takashi OSHIMA, Tatsuji MATSUURA, Yuichi OKUDA, Hideo NAKANE, Takaya YAMAMOTO, Keisuke KIMURA
  • Publication number: 20150236737
    Abstract: In a system including analog circuits of multichannel, channels which have a short distance therebetween are grouped so as to be included in the same group. During a reception period, a common correction signal is supplied to master channels allocated to the respective groups, and received signals are supplied to slave channels other than the master channels. A correction coefficient which tracks a characteristic fluctuation of each group is continuously searched for through continuous comparison between outputs of the respective master channels, and an output of each slave channel is corrected by using the correction coefficient of a group including the slave channel.
    Type: Application
    Filed: January 12, 2015
    Publication date: August 20, 2015
    Inventors: Yuki Okada, Takashi Oshima
  • Publication number: 20150229322
    Abstract: A differential signal is amplified by passive amplification which does not a reference of a common-mode voltage. At this time, the voltage of the differential signal is passive-amplified twice before carrying out a successive approximation type analog-digital conversion operation. The passive amplification is attained by providing a plurality of capacitances which carry out a sampling operation, and switching these connection relation by using switches. Without being accompanied by the increase of the consumed power and the chip size, an influence by the noise of s comparator is reduced to a half so that the effective resolution can be increased for one bit.
    Type: Application
    Filed: April 21, 2015
    Publication date: August 13, 2015
    Inventors: Yuichi OKUDA, Hideo NAKANE, Takaya YAMAMOTO, Keisuke KIMURA, Takashi OSHIMA, Tatsuji MATSUURA
  • Patent number: 9100034
    Abstract: A digital-correction-type A/D converter which is a charge sharing type and performing successive approximation is realized in a small area. The A/D converter is configured with an A/D conversion unit which is a charge sharing type and performing successive approximation, a digital correction unit which receives a digital output of the A/D conversion unit and performs digital correction to the digital output, and a holding unit which holds a test signal. A test signal of a common value from the holding unit is inputted into the A/D conversion unit in the first period and the second period. The A/D conversion correction coefficient for the digital correction unit is calculated on the basis of the digital correction result of the digital correction unit in the first period, and the digital correction result of the digital correction unit in the second period.
    Type: Grant
    Filed: March 10, 2014
    Date of Patent: August 4, 2015
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventors: Takashi Oshima, Tatsuji Matsuura, Yuichi Okuda, Hideo Nakane, Takaya Yamamoto, Keisuke Kimura
  • Patent number: 9054726
    Abstract: A differential signal is amplified by passive amplification which does not a reference of a common-mode voltage. At this time, the voltage of the differential signal is passive-amplified twice before carrying out a successive approximation type analog-digital conversion operation. The passive amplification is attained by providing a plurality of capacitances which carry out a sampling operation, and switching these connection relation by using switches. Without being accompanied by the increase of the consumed power and the chip size, an influence by the noise of s comparator is reduced to a half so that the effective resolution can be increased for one bit.
    Type: Grant
    Filed: January 21, 2014
    Date of Patent: June 9, 2015
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventors: Yuichi Okuda, Hideo Nakane, Takaya Yamamoto, Keisuke Kimura, Takashi Oshima, Tatsuji Matsuura
  • Patent number: 9054723
    Abstract: To compensate for non-linearity of an AD conversion unit and non-linearity of a DA conversion unit in an electronic system including the DA conversion unit and the AD conversion unit, an electronic system includes an A/D conversion unit, a D/A conversion unit, an AD conversion compensation unit, a DA conversion compensation unit, and a calibration unit. During a calibration operation period, the calibration unit sets an operating characteristic of the AD conversion compensation unit and an operating characteristic of the DA conversion compensation unit. The operating characteristic of the AD conversion compensation unit set during the calibration operation period compensates for non-linearity of AD conversion of the A/D conversion unit. The operating characteristic of the DA conversion compensation unit set during the calibration operation period compensates for non-linearity of DA conversion of the D/A conversion unit.
    Type: Grant
    Filed: May 12, 2014
    Date of Patent: June 9, 2015
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventors: Takashi Oshima, Tatsuji Matsuura, Yuichi Okuda, Hideo Nakane, Takaya Yamamoto, Keisuke Kimura
  • Patent number: 8933831
    Abstract: The influence of a jitter of a sampling clock of an analog-to-digital converter is digitally corrected at low power consumption. The sampling clock of the analog-to-digital converter is generated by a phase locked loop (PLL) using a reference clock, which has a lower frequency and lower jitter than the sampling clock, as a source oscillation. A time-to-digital converter (TDC) converts a timing error at a timing where the sampling clock and the reference clock are synchronized with each other into a digital value. A timing error at a sampling timing where the reference clock is not present is generated by interpolating a detected timing error. Thus, a jitter value of the sampling clock at each sampling timing is obtained. A sampling voltage error is calculated from the jitter value and the output of the analog-to-digital converter is digitally corrected.
    Type: Grant
    Filed: August 8, 2012
    Date of Patent: January 13, 2015
    Assignee: Hitachi, Ltd.
    Inventors: Takashi Oshima, Yohei Nakamura
  • Patent number: 8922407
    Abstract: A reference A/D conversion unit is connected in parallel to an input common to a time-interleaved A/D converter to be a calibration target, and the output of each unitary A/D conversion unit which makes up the time-interleaved A/D converter is calibrated in a digital region by using a low-speed high-resolution A/D conversion result output from the reference A/D conversion unit. Also, fCLK/N (fCLK represents an overall sampling rate of the time-interleaved A/D converter, and N is relatively prime to the number of unitary A/D conversion units connected in parallel M) is set as the operation clock frequency of the reference A/D conversion unit. Samplings of all unitary A/D conversion units can be sequentially synchronized with the sampling of the reference A/D conversion unit, and the operation clock frequency of the reference A/D converter can be made N times slower than the overall sampling rate of the time-interleaved A/D converter.
    Type: Grant
    Filed: April 30, 2014
    Date of Patent: December 30, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Takashi Oshima, Taizo Yamawaki, Tomomi Takahashi
  • Publication number: 20140333459
    Abstract: To compensate for non-linearity of an AD conversion unit and non-linearity of a DA conversion unit in an electronic system including the DA conversion unit and the AD conversion unit, an electronic system includes an A/D conversion unit, a D/A conversion unit, an AD conversion compensation unit, a DA conversion compensation unit, and a calibration unit. During a calibration operation period, the calibration unit sets an operating characteristic of the AD conversion compensation unit and an operating characteristic of the DA conversion compensation unit. The operating characteristic of the AD conversion compensation unit set during the calibration operation period compensates for non-linearity of AD conversion of the A/D conversion unit. The operating characteristic of the DA conversion compensation unit set during the calibration operation period compensates for non-linearity of DA conversion of the D/A conversion unit.
    Type: Application
    Filed: May 12, 2014
    Publication date: November 13, 2014
    Applicant: RENESAS ELECTRONICS CORPORATION
    Inventors: Takashi OSHIMA, Tatsuji MATSUURA, Yuichi OKUDA, Hideo NAKANE, Takaya YAMAMOTO, Keisuke KIMURA
  • Publication number: 20140253352
    Abstract: A digital-correction-type A/D converter which is a charge sharing type and performing successive approximation is realized in a small area. The A/D converter is configured with an A/D conversion unit which is a charge sharing type and performing successive approximation, a digital correction unit which receives a digital output of the A/D conversion unit and performs digital correction to the digital output, and a holding unit which holds a test signal. A test signal of a common value from the holding unit is inputted into the A/D conversion unit in the first period and the second period. The A/D conversion correction coefficient for the digital correction unit is calculated on the basis of the digital correction result of the digital correction unit in the first period, and the digital correction result of the digital correction unit in the second period.
    Type: Application
    Filed: March 10, 2014
    Publication date: September 11, 2014
    Applicant: RENESAS ELECTRONICS CORPORATION
    Inventors: Takashi OSHIMA, Tatsuji MATSUURA, Yuichi OKUDA, Hideo NAKANE, Takaya YAMAMOTO, Keisuke KIMURA
  • Publication number: 20140232578
    Abstract: A reference A/D conversion unit is connected in parallel to an input common to a time-interleaved A/D converter to be a calibration target, and the output of each unitary A/D conversion unit which makes up the time-interleaved A/D converter is calibrated in a digital region by using a low-speed high-resolution A/D conversion result output from the reference A/D conversion unit. Also, fCLK/N (fCLK represents an overall sampling rate of the time-interleaved A/D converter, and N is relatively prime to the number of unitary A/D conversion units connected in parallel M) is set as the operation clock frequency of the reference A/D conversion unit. Samplings of all unitary A/D conversion units can be sequentially synchronized with the sampling of the reference A/D conversion unit, and the operation clock frequency of the reference A/D converter can be made N times slower than the overall sampling rate of the time-interleaved A/D converter.
    Type: Application
    Filed: April 30, 2014
    Publication date: August 21, 2014
    Applicant: HITACHI, LTD.
    Inventors: Takashi OSHIMA, Taizo YAMAWAKI, Tomomi TAKAHASHI
  • Publication number: 20140203958
    Abstract: A differential signal is amplified by passive amplification which does not a reference of a common-mode voltage. At this time, the voltage of the differential signal is passive-amplified twice before carrying out a successive approximation type analog-digital conversion operation. The passive amplification is attained by providing a plurality of capacitances which carry out a sampling operation, and switching these connection relation by using switches. Without being accompanied by the increase of the consumed power and the chip size, an influence by the noise of s comparator is reduced to a half so that the effective resolution can be increased for one bit.
    Type: Application
    Filed: January 21, 2014
    Publication date: July 24, 2014
    Applicant: Renesas Electronics Corporation
    Inventors: Yuichi OKUDA, Hideo NAKANE, Takaya YAMAMOTO, Keisuke KIMURA, Takashi OSHIMA, Tatsuji MATSUURA
  • Patent number: 8736470
    Abstract: A reference A/D conversion unit is connected in parallel to an input common to a time-interleaved A/D converter to be a calibration target, and the output of each unitary A/D conversion unit which makes up the time-interleaved A/D converter is calibrated in a digital region by using a low-speed high-resolution A/D conversion result output from the reference A/D conversion unit. Also, fCLK/N (fCLK represents an overall sampling rate of the time-interleaved A/D converter, and N is relatively prime to the number of unitary A/D conversion units connected in parallel M) is set as the operation clock frequency of the reference A/D conversion unit. Samplings of all unitary A/D conversion units can be sequentially synchronized with the sampling of the reference A/D conversion unit, and the operation clock frequency of the reference A/D converter can be made N times slower than the overall sampling rate of the time-interleaved A/D converter.
    Type: Grant
    Filed: December 28, 2011
    Date of Patent: May 27, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Takashi Oshima, Taizo Yamawaki, Tomomi Takahashi
  • Patent number: 8525712
    Abstract: To improve resolution of a built-in A/D converter by reducing the area occupied by a chip of the built-in A/D converter in a semiconductor integrated circuit that is mounted in an on-vehicle millimeter wave radar device and which incorporates an A/D converter and an MPU. In the semiconductor integrated circuit, a plurality of reception signals of the radar device is A/D-converted by a single digital correction type A/D converter. The digital correction type A/D converter of the single A/D converter is a foreground digital correction type A/D converter that sequentially A/D-converts the reception signals output from a multiplexer of a receiving interface. The single A/D converter includes a pipeline type A/D converter having a plurality of cascade-coupled converters. The semiconductor integrated circuit comprises a correction signal generating unit, a digital correction D/A converter, and a digital correction unit for digital correction.
    Type: Grant
    Filed: August 1, 2011
    Date of Patent: September 3, 2013
    Assignee: Renesas Electronics Corporation
    Inventors: Takashi Oshima, Tatsuji Matsuura, Naoki Yada, Takahiro Miki, Akihiro Kitagawa, Tetsuo Matsui, Kunihiko Usui
  • Publication number: 20130191705
    Abstract: According to an embodiment, a semiconductor storage device includes an error correction processing unit that executes encoding process related data to be dispersedly written over a plurality of memory areas and decoding process related data dispersedly written over the plurality of memory areas. A transfer management unit determines whether or not data related to the data transfer request is a target of the error correction process and causes the error correction processing unit to execute the error correction process only with respect to the data determined as the target of the error correction process.
    Type: Application
    Filed: December 15, 2011
    Publication date: July 25, 2013
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Kouji Watanabe, Toshikatsu Hida, Takashi Oshima
  • Publication number: 20130179750
    Abstract: According to one embodiment, a semiconductor storage device includes a nonvolatile semiconductor memory, a temporary storage buffer that temporarily stores writing data to be written to the nonvolatile semiconductor memory, and a coding processing unit that divides coding target data of an error correction code into two or more divided data and writes an error correction code obtained by performing an error correction coding process based on the divided data stored in the temporary storage buffer to the temporary storage buffer as an intermediate code.
    Type: Application
    Filed: December 15, 2011
    Publication date: July 11, 2013
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Toshikatsu Hida, Takashi Oshima, Kouji Watanabe
  • Patent number: 8456335
    Abstract: In a successive approximation ADC, resolution is limited because a distortion occurs in an A/D conversion result due to a voltage dependence of a sampling capacitance. An A/D converter includes a sampling capacitor part in which capacitors equal in capacitance value to each other are connected inversely, a successive approximation A/D conversion part that conducts A/D conversion on the sampling charge, a digital correction part that corrects capacitance variation of internal DAC capacitors in the successive approximation A/D conversion part, and a digital correction part that digitally corrects a third-order or more factor of a voltage dependence of the sampling charge.
    Type: Grant
    Filed: November 16, 2011
    Date of Patent: June 4, 2013
    Assignee: Hitachi, Ltd.
    Inventor: Takashi Oshima
  • Publication number: 20130058437
    Abstract: The influence of a jitter of a sampling clock of an analog-to-digital converter is digitally corrected at low power consumption. The sampling clock of the analog-to-digital converter is generated by a phase locked loop (PLL) using a reference clock, which has a lower frequency and lower jitter than the sampling clock, as a source oscillation. A time-to-digital converter (TDC) converts a timing error at a timing where the sampling clock and the reference clock are synchronized with each other into a digital value. Incidentally, a timing error at a sampling timing where the reference clock is not present is generated by interpolating a detected timing error. Thus, a jitter value of the sampling clock at each sampling timing is obtained. A sampling voltage error is calculated from the jitter value and the output of the analog-to-digital converter is digitally corrected.
    Type: Application
    Filed: August 8, 2012
    Publication date: March 7, 2013
    Inventors: Takashi OSHIMA, Yohei Nakamura
  • Publication number: 20130049999
    Abstract: A reference A/D conversion unit is connected in parallel to an input common to a time-interleaved A/D converter to be a calibration target, and the output of each unitary A/D conversion unit which makes up the time-interleaved A/D converter is calibrated in a digital region by using a low-speed high-resolution A/D conversion result output from the reference A/D conversion unit. Also, fCLK/N (fCLK represents an overall sampling rate of the time-interleaved A/D converter, and N is relatively prime to the number of unitary A/D conversion units connected in parallel M) is set as the operation clock frequency of the reference A/D conversion unit. Samplings of all unitary A/D conversion units can be sequentially synchronized with the sampling of the reference A/D conversion unit, and the operation clock frequency of the reference A/D converter can be made N times slower than the overall sampling rate of the time-interleaved A/D converter.
    Type: Application
    Filed: December 28, 2011
    Publication date: February 28, 2013
    Inventors: TAKASHI OSHIMA, Taizo Yamawaki, Tomomi Takahashi
  • Publication number: 20120133534
    Abstract: In a successive approximation ADC, resolution is limited because a distortion occurs in an A/D conversion result due to a voltage dependence of a sampling capacitance. An A/D converter includes a sampling capacitor part in which capacitors equal in capacitance value to each other are connected inversely, a successive approximation A/D conversion part that conducts A/D conversion on the sampling charge, a digital correction part that corrects capacitance variation of internal DAC capacitors in the successive approximation A/D conversion part, and a digital correction part that digitally corrects a third-order or more factor of a voltage dependence of the sampling charge.
    Type: Application
    Filed: November 16, 2011
    Publication date: May 31, 2012
    Applicant: Hitachi, Ltd.
    Inventor: Takashi OSHIMA